Question: Simplify the following expression: $q = \dfrac{y}{2} - \dfrac{y}{6}$
In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $2$ and $6$ $\lcm(2, 6) = 6$ $ q = \dfrac{3}{3} \cdot \dfrac{y}{2} - \dfrac{1}{1} \cdot \dfrac{y}{6} $ $q = \dfrac{3y}{6} - \dfrac{y}{6}$ $q = \dfrac{3y -y}{6}$ $q = \dfrac{2y}{6}$ Simplify the expression by dividing the numerator and denominator by 2: $q = \dfrac{y}{3}$